Implement auto update for macOS and linux

Author: juho05

go.mod

@@ -1,6 +1,6 @@
 module github.com/code-game-project/codegame-cli
 
-go 1.18
+go 1.19
 
 require (
 	github.com/Bananenpro/cli v0.3.0

main.go

@@ -1,7 +1,102 @@
 package main
 
-import "github.com/code-game-project/codegame-cli/cmd"
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/Bananenpro/cli"
+	"github.com/adrg/xdg"
+	"github.com/code-game-project/go-utils/external"
+	"github.com/code-game-project/go-utils/semver"
+
+	cgExec "github.com/code-game-project/go-utils/exec"
+
+	"github.com/code-game-project/codegame-cli/cmd"
+)
+
+const Version = "0.7.1"
 
 func main() {
+	checkVersion()
 	cmd.Execute()
 }
+
+// checkVersion prints a warning, if there is a newer version of codegame-cli available.
+// On macOS and linux the user is offered to update automatically.
+func checkVersion() {
+	latest, err := getLatestVersion()
+	if err != nil {
+		return
+	}
+
+	currentMajor, currentMinor, currentPatch, err := semver.ParseVersion(Version)
+	if err != nil {
+		return
+	}
+
+	latestMajor, latestMinor, latestPatch, err := semver.ParseVersion(latest)
+	if err != nil {
+		return
+	}
+
+	if latestMajor > currentMajor || (latestMajor == currentMajor && latestMinor > currentMinor) || (latestMajor == currentMajor && latestMinor == currentMinor && latestPatch > currentPatch) {
+		_, shErr := exec.LookPath("sh")
+		_, sudoErr := exec.LookPath("sudo")
+		_, curlErr := exec.LookPath("curl")
+		_, tarErr := exec.LookPath("tar")
+		cgBin, codegameErr := os.Stat("/usr/local/bin/codegame")
+		if codegameErr == nil && !cgBin.IsDir() && shErr == nil && sudoErr == nil && curlErr == nil && tarErr == nil && (runtime.GOOS == "darwin" || runtime.GOOS == "linux") {
+			update()
+		} else {
+			cli.Warn("You are using an old version of codegame-cli (v%s).\nUpdate to the latest version (v%s): https://github.com/code-game-project/codegame-cli#installation", Version, latest)
+		}
+	}
+}
+
+func update() {
+	yes, err := cli.YesNo("A new version is available. Do you want to update now?", true)
+	if err != nil {
+		os.Exit(0)
+	}
+	if !yes {
+		return
+	}
+
+	_, err = cgExec.Execute(false, "sh", "-c", fmt.Sprintf("curl -L https://github.com/code-game-project/codegame-cli/releases/latest/download/codegame-cli-%s-%s.tar.gz | tar -xz codegame && sudo mv codegame /usr/local/bin", runtime.GOOS, runtime.GOARCH))
+	if err != nil {
+		cli.Error("Update failed.")
+		os.Exit(1)
+	}
+	cli.Success("Update successful.")
+	os.Exit(0)
+}
+
+func getLatestVersion() (string, error) {
+	cacheDir := filepath.Join(xdg.CacheHome, "codegame", "cli")
+	os.MkdirAll(cacheDir, 0o755)
+
+	content, err := os.ReadFile(filepath.Join(cacheDir, "latest_version"))
+	if err == nil {
+		parts := strings.Split(string(content), "\n")
+		if len(parts) >= 2 {
+			cacheTime, err := strconv.Atoi(parts[0])
+			if err == nil && time.Now().Unix()-int64(cacheTime) <= 60*60*24 {
+				return parts[1], nil
+			}
+		}
+	}
+
+	tag, err := external.LatestGithubTag("code-game-project", "codegame-cli")
+	if err != nil {
+		return "", err
+	}
+	version := strings.TrimPrefix(tag, "v")
+	os.WriteFile(filepath.Join(cacheDir, "latest_version"), []byte(fmt.Sprintf("%d\n%s", time.Now().Unix(), version)), 0o644)
+	return version, nil
+}